# Relationship history for MSHA mine 0301236

Current hierarchy: **R O T Inc → Lincoln County Sand & Gravel → Lincoln County Sand And Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** L B Mangum & Sons → Lincoln County Sand And Gravel; 1950-01-01 to 1978-09-26; source msha-controller-operator-history
- **controller_controls_mine:** Mangum Floyd → Lincoln County Sand And Gravel; 1950-01-01 to 1978-09-26; source msha-controller-operator-history
- **controller_controls_operator:** Mangum Floyd → L B Mangum & Sons; 1950-01-01 to 1978-09-26; source msha-controller-operator-history
- **operator_operates_mine:** T A Edwards Gravel Company → Lincoln County Sand And Gravel; 1978-09-27 to 1979-08-15; source msha-controller-operator-history
- **controller_controls_mine:** Edwards T A → Lincoln County Sand And Gravel; 1978-09-27 to 1979-08-15; source msha-controller-operator-history
- **controller_controls_operator:** Edwards T A → T A Edwards Gravel Company; 1978-09-27 to 1979-08-15; source msha-controller-operator-history
- **operator_operates_mine:** Pennington Dirt & Gravel → Lincoln County Sand And Gravel; 1979-08-16 to 1980-06-11; source msha-controller-operator-history
- **controller_controls_mine:** Pennington Donald → Lincoln County Sand And Gravel; 1979-08-16 to 1980-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Pennington Donald → Pennington Dirt & Gravel; 1979-08-16 to 1980-06-11; source msha-controller-operator-history
- **operator_operates_mine:** Lincoln County Sand & Gravel → Lincoln County Sand And Gravel; 1980-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** R O T Inc → Lincoln County Sand And Gravel; 1980-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** R O T Inc → Lincoln County Sand & Gravel; 1980-06-12 to current/open; source msha-controller-operator-history